ptrace: wait_task_zombie: s/->parent/->real_parent/

Change wait_task_zombie() to use ->real_parent instead of ->parent.  We
could even use current afaics, but ->real_parent is more clean.

We know that the child is not ptrace_reparented() and thus they are equal.
 But we should avoid using task_struct->parent, we are going to remove it.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/exit.c b/kernel/exit.c
index 938cceebb9ad9d6d401d642bdcbe775384068878..826e1dc8168be19e090c01c48cb86286c57610cd 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1204,7 +1204,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
                 * p->signal fields, because they are only touched by
                 * __exit_signal, which runs with tasklist_lock
                 * write-locked anyway, and so is excluded here.  We do
-                * need to protect the access to p->parent->signal fields,
+                * need to protect the access to parent->signal fields,
                 * as other threads in the parent group can be right
                 * here reaping other children at the same time.
                 *
@@ -1213,8 +1213,8 @@ static int wait_task_zombie(struct task_struct *p, int options,
                 * group including the group leader.
                 */
                thread_group_cputime(p, &cputime);
-               spin_lock_irq(&p->parent->sighand->siglock);
-               psig = p->parent->signal;
+               spin_lock_irq(&p->real_parent->sighand->siglock);
+               psig = p->real_parent->signal;
                sig = p->signal;
                psig->cutime =
                        cputime_add(psig->cutime,
@@ -1245,7 +1245,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
                        sig->oublock + sig->coublock;
                task_io_accounting_add(&psig->ioac, &p->ioac);
                task_io_accounting_add(&psig->ioac, &sig->ioac);
-               spin_unlock_irq(&p->parent->sighand->siglock);
+               spin_unlock_irq(&p->real_parent->sighand->siglock);
        }
 
        /*